Water on MgO(100) - An infrared study at ambient temperatures

Transmission Fourier transform infrared spectroscopy (FTIR) is used to investigate water adsorbed on the (100) face of MgO under ambient conditions. From these measurements, we find that water reversibly adsorbs to MgO(100) creating liquid-like layers at temperatures ranging from -10 degrees C to 40 degrees C with slight hysteresis seen during a complete adsorption/desorption cycle. The adsorption isotherms of water on MgO(100), throughout the entire temperature range sampled, resemble a typical BET plot, which coupled with the fact that IR absorption due to the OH stretch of the adsorbed water does not change as a function of coverage, suggests that the layer grows in via three-dimensional island formation. Thermodynamic analysis indicates three distinct regions of water adlayer growth. (c) 2005 Elsevier B.V. All rights reserved.